Engine Re Conditioning Specialists | BMW Engine
If you are starting a long-term engine building project and want the best out of an engine, start with a bare cylinder block. The block is the foundation of any project. Every other component in the engine ultimately depends on it. More time and effort and expense are devoted to preparing the block than any other component. Deburr all the irregularities from when the block was cast and soak it overnight in a caustic soda tank. Remove it and wash it off with a degreaser such as Prepsol.
Align boring is always a good idea, especially when the block has weathered, meaning that the metal has been stressed to a point of no return and has taken to that shape. Torque all your main bearing caps to the usual settings and send it to your motor engineering shop for align boring and honing. Align boring and honing guarantees a perfect line-up through all the main bearing caps and ensures that there is no drag on any of the bearing shells. Not any engineering shop can perform this boring so find out where it can be done closest to you.
The next process is to bore the block to suit your pistons and chamfer the bore entry to 60 degrees. Hone the bores with a 280-320 grit hone. Align the holes between the bearings and the saddles and elongate the bearing shells as necessary to fit the oil gallery outlets perfectly.
When all the machining, honing and grinding is done it’s time to wash the block clean. The object of this exercise is to remove all the grit, dirt and machining chips that have accumulated in the block. Remove all oil channel grub screws and plugs. Gun and rifle cleaning kits are useful for getting this job done right. Clean the block with a powerful degreaser and engine cleaner. Use hot water and assorted scrubbing brushes, bottlebrushes and a high pressure WAP sprayer should do the job. Repeat this process. Blow the block clean and dry with a compressed air gun making sure there are no obstructions, the air gun will usually help move any stubborn dirt.
Lubricate the entire block liberally with an aerosol lubricant like Q-20 to prevent rust formation. The cleaning process must be one of high importance and done in a clinical manner. Your block must be ‘as clean as a whistle’. Just one grain of debris can destroy an entire project. Make sure you don’t skimp here before you assemble all your newly purchased and balanced engine components.
Again, take your time to check and check, and check again!
CLICK HERE for new and used motor spares and accessories in South Africa.
CLICK HERE for engine blueprinting and motor engineering.
